Electric-arc welding apparatus



Nov. 8, 1927. 1,648,563

H. D. MORTON ELECTRIC ARC WELDING APPARATUS Original Filed Jan, 27, 1917 2 Sheets-Sheet 2 E as E 68 a J7 58 I Patented Nov. 8, 1927.

UNITED STATES HARRY n. Mo'R'roN, or NEW YORK, N. Y. COMPANY, or DETROIT, MICHIGA ASSIGNOR TO AUTOMATIC ARC WELDING N, A CORPORATION OF MICHIGAN.

ELECTRIC-ARC WELDING APPARATUS.

Original application filed January 27, 1917, Serial No. 144,930. Renewed August 14, 1917, Serial No. 186,238. Divided and this application filed August 20, 1927. Serial No. 214,264.

My invention relates to electric arc welding in which a metallic electrode in the form of a strip of wire or welding material is fed to the arc and to the work, which constitutes the other electrode in the circuit.

7 The present application constitutes a division of my copending application Serial No. 186,238, filed August 14, 1917 (renewal of application Serial No. 144,930, filed J anu- 10 ary 27, 1917) The present invention is particularly directed to apparatus wherein the control of the welding strip is effected by the action of clutch devices, which are pref-,

erably of the electro-magnetic type, governed by a variable characteristic of the welding circuit.

The following is a description of electric arc welding apparatus embodying the present invention in its preferred form, but it will be understood that various modifications and changes may be made therein without departing from the spirit of the invention and without exceeding the scope of the claims.

25 The invention will best be understood by reference to the accompanying drawings, wherein Fig. 1 is a diagrammatic illustration of a system and apparatus embodying the present invention; and Fig. 2 is a view on an enlarged scale illustrating the changespeed mechanism shown in connection withthe system of Fig. 1.

Like reference characters indicate like parts in the two drawings.

I have found that it is essential for the practical successful operation of this form of electric arc welding that an equilibrium be maintained between the rate of fusing of a strip of welding material and the rate at which said welding material is fed to the arc. I have found that under some conditions and within narrow limits this e uilibrium is maintained by the arc itself WlllCh has, within certain limits, if the welding strip is con tinuously fed at a suitable constant rate, a compensatory action as follows: when the arc shortens the resistance decreases, the amperage rises, and this rise in amperage results in the welding strip fusing more rapidly, thereby causing the arc to lengthen.

Conversely, if the arc lengthens the resistance is increased, the amperage decreases proportionately, the welding stri is fused more slowly and the continuous y moving welding strip restores the arc to its normal length.

lVhile as I have stated this compensatory action of the arc may maintain the necessary equilibrium between the rate of fusing and the rate of welding strip feed, this applies only within relatively narrow limits. I have found in practice that due perhaps to differences in the fusibility or conductivity of the welding strip or of the work it frequently occurs that the range of compensatory action of the arc is insufiicient to prevent either a contacting of the welding strip with the work or a rupture of the are due to its becoming too long.

To overcome this difiiculty I have devised a method and system by means of which the equilibrium is maintalned within any desired limit by controlling the rate at which the welding strip is fed to the arc.

Referring to Figure 1, 10 designates an electric generator or other suitable source of current for supplying electric welding current to the welding circuit which includes the wire 11, solenoid 12, wire 13, welding strip work 15 and return wire 16. It will e understood that in welding operation an arc is formed at a between the end of the welding strip and the groove 17 in the work 15. For the purpose of welding two plates or parts together the ends to be joined are tapered and placed in abutting relation thereby forming the groove 17 and the intense heat of the are at a rapidly melts the metallic strip 14 and deposits it in the groove 17 thereby uniting the pieces of metal at the joint 18. On account of the fact that the intense heat at the are a melts the strip 14 very rapidly it is necessary to feed this strip from a reel to the arc uninterruptedly.

and automatically to produce a homogeneous weld.

The feeding mechanism for feeding the metallic welding strip. 14 to the work 15 consists of two feed rollers 19 and 20, pref erably provided with serrated perimeters, located to receive between them the welding strip 14 which is in the form of a wire. The feed rolls 19 and 20 are rotatably mounted in a welding head 21 which is indicated in dotted lines and provided with suitable guides for the welding strip 14.

The feed rolls may be geared'together and,

are'driven by a shaft 22 connected bythe gears-23 and 24 to a jack shaft 25. The

work in the present case consists of two cylindrical members which'are to be joined by an. annular Weld and in order .to do this the Work is rotated while the welding strip center 26 and a mandrel 27. The mandrel 27 is connected by the gear 28 to a gear 29 keyed to the shaft 25. It will be seen that by this arrangement the jack shaft 25 drives the feed rolls 19 and 20 and also produces a relative movement between the work and the welding head while the strip 14 is being fed to the work and the molten metal is being deposited on the work. It i will also be noted that the feed rolls are driven at a higher speed than-the work, since the ratio of the gears 23 and 24 is about as 1 to 7. The gears 28 and 29 being of the same size will cause the work 15 to be rotated atthe same speed as the shaft25. A fixed rel.- tion is preserved between the feed of the welding strip 14 and the rate of movement of thework 15 but the feed of the welding strip 14 is varied because the welding strip cannot be made uniform throughoutits entire length. Diiferent portions of the welding strip may vary in fusibility or be of slightly differing diameters and the strip will therefore fuse at difi'erent rates, When.

the welding strip 14 fuses very rapidly there is a danger that the are at a may suddenly become so long as'to rupture and then in order to start the are it is necessary to bring the end of the strip 14 again into contact with the work. Conversely, if the feed of the stri '14 to the are a is more rapid than the sion of the welding strip, the welding strip may be fed againstthe work and cause a short circuit which isinjurious to the work and also requires/separating the electrodes to again rm an arc.

- As heretofore explained the are a has a compensatory action so that within narrow limits the difference in the fusibilit of the welding strip '14 will be automatical y taken care ofby the are itself. However, in order to take care of the extreme differences of'fusibility of the welding stri 14 and irregularities in the contour 0 thereby 'maintai the are I have devised an automatic contro .mechanism which is r6 .sponsive to the changes the amperage of the are ,a resulting from the varying rate i of melting of the welding strip and from irregularities in the contour of the work;

I and which .will alter the rate of feed of the welding strip 14 to correct the variations of 1 the are andthus" compensate for the difl'erences infusibility ofthe feeding strip.

My arrangement for changing the rate of' is corrected the are will rupture.

the work and arm 32 carries switch contacts34 and 35 at its outer end which are normally maintained between the switch contacts 36 and 37 by reason of the fact that the spring 31 is adjusted so as to hold the plunger 30 in equilibrium in the solenoid 12 while the value of the current flowing in the welding circuit is normal. This condition prevails when the are at a is normal, that is, when the feed of the welding strip 14 is at the proper rate to keep the area within certain predetermined limits which will produce a substantially homogeneous weld and prevent either short-circuiting of the welding strip or rupture of the arc. When an excess of current is caused to flow through the solenoid coil 12 due to the fact that the feed of the welding strip 14 is faster than its fusion, the plunger 30 will move downwardly and close the contacts 34 and 36 and energize the slow speed solenoid 38 by the following path: battery B, wire 39, wire 40, solenoid 38, wire 41, contacts 36 and 34, wire 42 back to battery B; When the slow speed solenoid 38 is energized it will cause the welding strip feeding mechanism to slow down and the normal length of arc will thereby be restored, by the s eed change mechanism S to be described. n the other hand when the flow of current in the welding circuit decreases on account of the fact that a part of the welding strip 14 fuses faster than it is fed to the are a, the are a will be lengthened and unless this condign e spring 31 overcomes the pull of .the solenoid '12 on the lunger 30 when this con dition exists an causes the contact 35 to engage the contact 37 thereby closing the local circuit which includes the high speed solenoid 43 by the following path battery B, wires 39 and 44, high speedsolenoid 43,. wire 45, contacts 37 and 35, wire 42 to battery B. By energizing the high speed sole-f noid 43 the change speed transmission S is caused to operate to speed up the feed of the welding strip to restore the are a to its 110;

The c an eed transmissionv is shown on a larger sca e' nFigure 2 and includes the slow speed solenoid38 and thehigh speed solenoid 43'. The armature 46. of the high speed solenoid 43 has a pin 47 which moves in the segmental slot 48 whereby it is conmal len nected to thenormzfl speed lever 49. The

normal speed lever 49 has its fulcrumat 50 and is connected at its short end to a pin 51, which fits in the groove of a clutch 52 connected to but slidable along the drive shaft 53 which may be a line shaft or the shaft of an electric motor or other driving'means. The pin 51 also has a lever 54 connected to it, the fulcrum of the latter being at 55. The long end of the lever 54 is providedwith a segmental slot 56 in which a pin 57 moves and by means of which the lever 54 is connected to the armature 58 of the slow speed solenoid 38. The clutch 52 is usually held in engagement with the corresponding clutch teeth of a normal speed gear 59 by means of the springs 60 and 61 attached to the long arms of the levers 49 and 54 respectively. The armature 46 of the high speed solenoid 43 is connected to the end of a lever 62 fulcrumed at 63. The sh orter end of the'lever 62 carries a pin 64 which moves in a groove of the high speed clutch 65. said clutch being connected to the shaft 53 but sliding thereon. The armature 58 of the slow speed solenoid 38 is connected to a lever 66 fulcrumed at 67 and carrying a pin68 which moves in a groove of the slow speed clutch 69, keyed to the shaft 53 but slidable thereon. The gears 59, 70 and 71 carried by the shaft 53 mesh with the gears 72, 73 and 74 keyed to the jack shaft.

When the arc lengthens the high speed solenoid-43 will be energized, attracting the armature 46, disengaging the clutch 52 from contact with the normal speed gear 59 and simultaneously causing the high speed clutch to engage the clutch teeth of the high speed gear which drives the shaft 25 through the gear 73 at a higher than normal speed thereby feeding the welding strip 1.4 more rapidly. Whenthe circuit of the solenoid 43 is broken as the result of the are having resumed its natural length, the spring 60 draws the armature 46 to the left, disengaging the high speed clutch 65 and reengaging the normal speed clutch 52.

When the arc shortens the circuit of the slow speed solenoid 38 is closed as already explained, causing the armature 58 to movev to the right, disengaging the clutch 52 from contact with the clutch of the normal speed gear 59 and simultaneously causing the low speed clutch 69 to' engage the clutch teeth of the .low speed gear 71. The low speed gear 71 will then drive the jack shaft 25 at a lower than normal speed, restoring the arc to its normal length. When the .circuit of the solenoid 38 is broken as a result of the arc having resumed its natural length, the spring 61 draws the armature 58 to the left, disengaging the low speed clutch 69 and reengagin the normal speed clutch 52.

It wil be noted that the three clutches on the drive shaft-53am interlocking, i. e. but one can be engaged at a'time, the other'two being held automatically out of contact.

lizing the heat of When either lever 49 or lever 54 acts to disengage the clutch 52 there is a movement of the opposite lever but this movement does not affect the opposite armature with its high speed or low speed lever (as the case may be), for the reason that the segment of such opposite lever moves in the slotted portion of its armature, such armature remaining stationary.

It is to be understood that the system shown in Figure 1 is merely illustrative and that the well-known arc-starting devices, ballistic resistances, reactances, and manipulating means such as switches, etc., common in the art, are omitted; and that numerous other systems may be employed for carrying out the same method and obtaining the same results.

It is to be understood that when the contour of the work varies, it is necessary to vary the relation between the fusing rate and the feeding rate of the strip. For instance, if an elevation or proturbance in the work-is encountered, it then becomesnecessary to fuse the strip faster than it is fed. On the other hand, if a depression in the work is encountered, it becomes necessary to feed the strip faster than it is fused.

By the term a characteristic of the arc as'used in the claims, I intend to include such variable, utilizable properties as accompany the operation of an arc, and which are indicative of its normal or abnormal operation, such, for example, as its current, voltage, resistance, length, or energy absorption.

I claim:

1. In electric arc welding, a welding circuit including work material and a welding pencil, means for effecting relative movement between said work material and pencil, a relay responsive to variations in a characteristic of the welding circuit, and a. clutch controlled by said relay for governing said means for effecting relative movement.

2. In electric arc welding, a welding circuit including work material and awelding pencil, welding pencil feeding means, a clutch for regulating the speed of the feeding means, and a .relay controlling said clutch and governed by said welding circuit. 3. In electric arc welding, means for feeding a welding pencil to an arc struck between said pencil and work material, a relay responsive to changes .in arc length, and a clutch governed by the relay and controlling the said feeding means.

4. In electric ago welding, means for utithe arc to fuse'work material,said means comprising a welding circuit including two electrodes between which an arcais adapted to be struck, electro-feedchanges in arc length for controlling said' translating device.

6. In electric arc welding wherein an arc is adapted to be struck between work material and a welding pencil, means for effecting relative movement between said pencil and work material, a relay connected to" the welding circuit, an electro-responsive device controlled by therelay, and a clutch governed by the electro-Iesponsive device for varying the speed of said means for effect ing relative movement. v V

71 In electric arc welding wherein an arc is adapted tobe struck between work material and a welding pencil, means for feeding the welding pencil in order to maintain the are, a relay responsive to variations in a characteristic, of the arc, and a clutch governed by the relay and controlling the speed of the feeding means to regulate the are.

8. In electric arc welding whereinan arc is adapted to be struck between work material and a welding pencil, means for main taining the arc com rising welding pencil feeding means, a utch for varying the speed of said feeding means, and arelay responsive to changes in a characteristic of the are for controlling the movements of the clutch.

9. In electric arc welding wherein an arc is adapted to be struck between work material and a fusible-welding pencil, means for maintaining the arc comprising welding-pencil feeding means, a relay responsive to a characteristic of the welding circuit, and a clutch controlled by the relay and governing the feeding means and characterized by the fact that when .the arc shortens the feeding rate of the welding strip becomes\less than the fusing rate, and when the arc lengthens said-feeding ratebecomes greaterthanthe fusing rate.

10. 'Inelectric arc welding wherein an arc is struck between work material and a fusible welding strip included in a welding circuit, the combination of means for feeding said strip to the-arc, a relay controlled by the welding circuit, and a clutch governed by the relay and regulating the feeding means, whereby the length of rhe' arei maintainedsubstantially constant. i I 11. In electric arc welding, the combinationpf a welding circuit including work material'an d 'a welding electrode between which 3 an arcgis"a*"dapted to be struck, means for feeding the electrode to the arc, an electrical lating device for varying the speed of the feeding means to regulate the arc length.

12. In electric arc welding, a welding circuit including a welding pencil and work material between which an arc is adapted to his struck, electro-responsive control means connected to the welding circuit, an elect-roresponsive clutch device governed by said control means, and means controlled by said clutch device for feeding the welding pencil toward the work.

13. In electric arc welding, a welding circuit including a welding pencil and work materialbetween which an arc is adapted to be struck, a relay responsive to an electrical characteristic of the welding circuit, an electro-magnetic clutch controlled by said relay, and means controlled by said clutch for. feeding the welding pencil to the arc.

14. In electric arc welding, a welding circuit including work material and an elec trode between which an arc is adapted to be struck, means for feeding the electrode toward the work, driving means for said feeding means, a clutch between said driving means and feeding means, and a relay governed by the welding circuit for controlling said clutch.

15. In electric arc welding, a welding circuit including work material and ametallic welding strip between which an arc is adapted to be struck, means for feedingthe welding strip to the are, driving means for the. feeding means, a driving connection between said driving and feeding means, an electro-magneta for controlling saidconnection and electro-responsive means actuated by changes in arc length for controlling said electro-magnet.

16. In electric arc welding, a welding circuit including work material and a welding pencil between which an arc is adapted tobe struck, means for feeding the pencil to the arc, driving means for the feeding means, a driving connectlon between said driving and feeding means, an elect-ro-magnet controlling said connection, an electric circuit including the winding of said electro-magnet, and

means responsive to a characteristic of the Y ,welding circuit for controlling said lastnained circuit. 17. In a metallic electrode arc welding inathe normal speed gear normally connects the driving and driven shafts, and automatically acting means for causing the release of chine, the combination of a driving shaftg'a driven shaft, gearing connecting said shafts I qoinprising a low speed gear, a normal speed geara'nd a high speed gear, means whereby the normal speed-"gearing a d simultattic/ 3 3 ously causing either the high speed gear or the low speed gear to connect the driving shaft to the driven shaft,

18. In a metallic electrode arc welding machine, the combination of a driving shaft, normal, high and low speed gears on said driving shaft, a driven shaft, gearing on the driven shaft adapted to mesh with the gears on the driving shaft, means whereby the normal speed gear is normally connected to part of the gearing on the driven shaft, solenoids for controlling the connection of the high and low speed gears of the driving shaft to gearing on the driven shaft, and means for automatically actuating said solenoids to cause either one to release the normal speed gear and mechanically connect either the high or low speed gear to the driving shaft whereby either the high or low speed gear drives the driven shaft.

19. In a metallic electrode arc Welding machine, the combination of a driving shaft carrying high, normal and low speed gears, a driven shaft carrying gears meshing with the high, normal and low speed gears onthe chiving shaft, clutches for mechanically connecting the high, normal and low speed gears to the driving shaft, high speed and low speed solenoids for operating said clutches, means whereby said solenoids normally cause one of said clutches to mechanically connect the normal speed gear to the driving shaft,

an electric circuit for closing the circuit of either of said solenoids to energize the same, means whereby when the high speed solenoid is energized the first clutch is released to release the normal speed gear and a second clutch connects the high speed gear to the driving shaft, and means whereby when the low speed solenoid is energized the first gear is released to release the normal speed gear and connect the low speed gear to the driving shaft, r r

20 In a metallic electrode electric arc welding machine in which a welding strip constitutes one electrode and the work constitutes the other electrode, the combination of a welding strip carrier, means for effecting relative movement between the work and the welding strip carrier, means for feeding said welding strip from the carrier toward the work whereby molten inetal is deposited on the work while the carrier and work are moving relatively to each other, gearing for driving said strip feeding means, clutches controlling said gearing, solenoids actuating said clutches, electric circuits including said solenoids, switches controlling said electric circuits, and electro-magnetic means responsive to changes in the amperage of the are for operating said switches whereby changes in said are amperage vary the rate at which the welding strip is fed to the are.

HARRY D. MORTON.

CERTIFICATE OF CORRECTION.

Patent No. 1, 648, 563.-

Granted November 8, 1927, to

HARRY D. MORTON.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows:

Page 3, line 128, claim 4, for the word "electro" read "electrode"; and that the said Letters Patent should be read with this correction therein that the some may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of August, A, D. 1928.

(Seal) M. J, Moore, Acting Commissioner of Patents 

